Island



(Model) V '4 Sheba-Sheet v E. P. FROST. 1 Switch- Board forTele phoneLines. 7 N6. 237,512. Patented Feb. 8,1881.

Fig.1. Witnesses Inventor:

N. PETERS. PHOTO-LITNDGRAPIJER. WASHINGTOIL B. Q

(Modem 4 Sheets-Sheet '2. E. F. FROST. Switch Board for Telephone Lines.

Patented Feb. 8,1

Fig.1 I Inventor: 5/(4) 596-11 T139. 6. Witnesses N PETERS.FHOTOvUTNOGRAPHER, WASHINGYON D (Model) 4 Sheets-Sheet 3Q E.F.PROSTRSwitch Board for Telephone Lines. No. 237,512. Patented Feb. 8,1881.

N:PETERS. PHOTO-LITHOGHAFHER. WASHINGTZDN. D. C.

,4 Sheets-Sheet 4.

, 3.1. FROST. I Switch Board for Telephone Lines.

(Modgn) NO. 237,512. Patented Feb; 8, 1881.

liiagram 4'.

.Lane and Gr Iine and Gn liiagram 5.

Jtagr'am 6.

l nvn i or:

ufitnesses N.PEIERS,PHOTO-UTNDGRAFHER. WASHINGTON. a, 0.

UNrrE STATES "Aren't Price.

ELLIS F. FROST, OF PAWTUOKET, RHODE ISLAND, ASSIGNOR 0B ONE-HALF TOCHARLES H. M. BLAKE, OF WESTON, MASSACHUSETTS.

SWITCH-BOARD FOR TELEPHONE-LINES.

SPECIFICATION forming part of Letters Patent No. 287,512, dated February8, 1881.

Application filed July 26, 1880.

To all whom it may concern:

Be it known that I, ELLIs F. FRos'r, of Pawtucket,in the State of RhodeIsland, have invented certain Improvements in Switch- Boards forTelephone-Lines, of which the following is a specification.

One part of my invention consists in the use, in connection with two ormore telephone-cir-' cuits, of certain fixed contact plates, points, andsprings and certain shifting contact-plates, of long hand'levers, innumber double that of the telephone-circuits, operating the shiftingcontact-plates, and so pivoted that they move in parallel arcs, and thatwhile the range of motion of the operators hand is appreciable theactual switching mechanism is confined within a very narrow compass,thereby allowing a more compact and convenient arrangement of theswitch-board than any I have heretofore known. These last-namedadvantages are largely due to the fact that I have devised an outwardlycurved and vertically slotted switch board embodying suitablecontactpoints, ground, signaling, and llUBCOIHIBUIlUHS, and havecombined therewith switching-levers which occupy slots in said board'andare movable in parallel arcs toward and from the operator, and saidcombination constitutes another feature of my invention.

Another part of my invention consists in the use, on a switch-boardbelonging to two or more telephone-circuits, of a number of handleversequal in number to the number of circuits, the several levers havinguniform motions, and each being in electrical connection with a separateswitch mechanism to bring in its owntelephone-circuit, and working in aslot provided with a series of notches, the corresponding notches of thesaid slots being also in electrical connection with each other.

Myinvention consists, further, in connecting with the apparatus referredto above a single hand-telephone in such manner that the saidhand-telephone may be used in the entire circuit caused by the union ofany two of the telephone-circuits, or may be disconnected from themboth, or may be grounded in either independently of the other, all bythe use of the same hand-levers.

My invention consists, further, in connect- (ModeL) ing with the switchmechanism upon a switchboard, and at a central otlicc for connecting anddisconnecting two. or two of several, tele phone-circuits, independentcall-circuits with suitable contact points or springs, in such mannerthat the same hand-levers which are used to connect and disconnect thetelephonecircuits may also be used to bring in the callcircuits.

The invention consists, further, in certain details ofconstruction.hereinafterpointed mt.

In the drawings 1 have shown a switchboard adapted for use in connectionwith two telephonecircuits; but upon an examination.

ot' the numerous diagrams with which i have illustrated its use inconnection with the two circuits it will appear thatthe number oftelephone-circnits may be increased to any nnm' her. Upon examination itwill appear that the apparatus shown is in two sections, one belongingto each of the two telephonccit'- cuits, and each a duplicate of theother, excepting that the hand telephone is directly connected to butone. For convenience, with the exception ot the casing, which is commonto both sections, and with the further exce tion of certain wires, aswill appear, I have designated corresponding parts in the two sectionsby the same letter, adding, llli\\'ti\'t5l',"[() each letter in onesection a lignrel and in the other a tignre 2; or where I have found itconvenient to use the same letter twice or more in each section, I havein one section added odd numerals and in the other the next evennumerals.

Figure l is a iront elevation of so much of my apparatus as is seen wheninclosed in its casing, which is also shown. l ig. 2 is an inverted planof the same. Fig. 3 is a rear elevation of the same. Fig. 4 is a sectionon line 00 w-ot'Fig. 1, looking toward the middle of the casin Fig. 5 isa section on line y y of Fig. 1, looking in the opposite direction. Fig.6 is an enlarged view of acertain slot, 1), showing certain notcheslined with metal, and also, in section, a certain metallic hand-lever inits normal position. Fig. 7 is a similar view of another slot, 0, withlining-plates and lever. The remaining figures consist of diagrams inexplanationot' the electrical circuits.

The casing, which is of wood, is in the form of the casing of abeer-pump, the hand-levers which are used for operating the switchesbeing like the handles of a beer-pump.

A is the bottom of the casing; B, the front, curved in shape; 0 the twoends, and D D the back, the part D being hinged to the bottom A at a a,and opening to permit the adjustment of apparatus within. The curvedfront B has two long slots, 1) b through which work two brass levers, FF which are pivoted to the bottom A, within the casing, as shown, andtwo shorter slots, 0 0 through which, in the same manner, work two brasslevers, E E whose inner ends are rigidly secured to two woodenquadrants, G G which are pivoted to the bottom A, slots (1 and dpermitting movements of the quadrants corresponding to the movements ofthe levers E and E in the slots 0 and 0 The long slot 1) has fournotches, m 0 6 which are in part or wholly lined with brass, and theslot b has tourcorresponding brass-lined notches, e 0 e. The longslots 1) and b have also, respectively, for a lining at the head of theslots, short brass plates, 0 and 6 The shorter slots 0 and 0" haverespectively upon one side, as a lining, a long brass plate, f f and ashort brass plate,f f The quadrant G has upon one face, near its curvededge, along brass strip, g, and a short brass strip, the latter -onesection of the instrument, H is a long metallic spring, one end of whichis secured to the inside of the back of the casing, while the otherpresses always upon the strip g, whatever may be the position of thequadrant G.

, J is a short metallic sprin g, one end of which is secured to thebottom A, while the other presses always against the quadrant G upon thesame side as the spring H, being eitherin contact with strip 9 or strip9, according to the position of the quadrant. K is a long metallicspring, secured to the back of the casin g and pressing always upon theopposite face of the quadrant G, and, according to the position of thelatter, being either in'contact with strip or strip 1 and pressing uponthe same side of the quadrant G with spring K, and secured to the bottomA, is a short spring, S, in contact either with strip g or stripaccording to the position of the quadrant. 1n the other section,respectively corresponding to the parts H, 9, J 9 K, 9 g, and S, and

' used in connection with the quadrant G are precisely similar parts,(not shown, however, excepting in the diagram s,) H 9 J 9 K g g and S.

L, M, N, O, P, Q, andR are binding-screws in section 1 in immediateconnection with apparatus worked by hand-levers E and F,whi1e L M N 0 P6),, and R are similar bindingscrews in connection with apparatus workedby hand-levers E and F in section 2. In the bottom of the casing insection 1 are four holes, j,j ,j andj, whiie in section 2 are fourholes, jZjflj", andj. A wire, 20, connects notch cin slot 1) with notche in slot b the said wire in its passage passing through holes j and 9'(This wire and all other wires to which reference is made in thisdescription are shown only in the diagrams; and this is true, also, ofhand-telephones, call-bells, batteries, distant stations, and grounds.)In like manner wire 10 connects notches c and 6 passing through holes 9'and j. Wires 10 and 10 make similar connections. Other electricalconnections are as follows: Binding-screws O O are in electricalcontact, respectively, with brass liningplates 0 and 6 at the head ofslots b and b Binding-screws M and M are in contact with long springsKand K Binding-screws L and L are in contact with long springs H and HBindingscrews P and I are respectively connected by wires u and v withhand-levers E and E Binding-screws N and N enter the slots 0 and 0 inorder that the hand-levers E and E may at times be pressed against them,these hand-levers being so sprungthat in their upper normal. positionsthey do not touch binding-screws I and N Wire 10 connects binding-screwL with binding-screw L and wire to connects binding-screw M withbinding-screw M. A hand-telephone, T, is placed in section 1 on a wire,25, connecting bindingscrews L and M. This single hand-telephone, aswill hereinafter appear, is used for all the sections. A wire, 0,passing through a call-bell, connects binding-screw U with the ground,and in like manner a wire,0", passing through another call-bell,connects binding-screw O with ground. A linewire, Z, passes frombinding-screw P through all the stations of section 1 to ground, and inlike manner a linewire, l passes from binding-screw P through all thestations of section 2 to ground. Binding-screw Q is grounded by wire q,and binding-screw Q is grounded by wire Q2. A wire y, connects brasslining-strip f with spring J in section 1, and wire p connects f with Jin section 2. Wire 2 connects short brass lining-strip f withbinding-screw It, and wire 2 connects f with R". ire r connectshandlever F with spring S, and wire r connects hand-lever I with springS The manner of operating this apparatus, its conveniences andadvantages, are shownin the diagrams, where, unless otherwise stated,similar letters refer to parts designated by like letters in the otherfigures. For clearness in illustration, however,- I have substituted forthe quadrants having brass strips upon two faces and working between twosets of springs straight bars with four contact-strips, each upon asingle face; and,placing the springs at a little distance, I haverepresented the shifting contacts between strips and springs by brokenlines, as will readily appear.

The operation is as follows:

1. In the normal condition of the apparatus all the hand-levers E, E F,and F are up, E and E being in contact, respectively, with the upperends of the lining-plates f j' in slots 0 c andF and F being in contact,respectively, with plates 0 6 in slots b and D The circuit at section 1is from out-stations belonging to that section, by wire 1, bindingscrewP, wire '0, hand-lever E, lining-plate f, (in slot 0,) wire 3 spring J,strip 9 spring b", wire r, hand-lever F, plate 6, (in slot b,)bintlingscrew 0, wire 0, through call-bell belonging to section 1, toground. This is the calling-circuit for out-stations on telephonelinebelonging to section 1. For section 2 there is a precisely similarcircuit. which may be easily traced in diagram 4, although a difl'erentcondition of the apparatus is there shown, a difi'erent circuit havingbeen there established. In the normal condition of the apparatus the twotelephone-circuits are not connected.

2. A person at an out-station belonging to section 1 having called thecentral station, the operator at the central station pulls the handleverE about halfway down in slot 0. This establishes a telephonecircuit, asshown in diagram 2-viz., from ground at central station, by wire 0, tobinding-screw O, brass plate 0 hand-lever F, by wire r to short spring5, to strip 9 (on quadrant G,) long spring K, binding-screw M, throughthe telephone T to binding-screw L, long spring H, strip g, (on quadrantG,) small spring J, by wire 3/ to long lining-platef", (in slot 0,)hand-lever E, by wire 'vto binding-screw P, through the outstations ofsection 1 to ground.

3. A similar telephone-circuit for section 2 can be easily traced byreference to diagram 4, although the diagram is not drawn to illustratethis circuit, the connections shown being for another purposethat is, ifa person at an out-station in section 2 has called the central station,the operator pulls the hand-lever E half-way down in slot 0 and thecircuit is from ground at central station, by wire 0 to binding-screwplate e hand-lever F, wire r spring S ,-strip g spring K binding-screw Mwire to, bindingscrew M, hamltelephone T,binding-screw L, wire 10binding-screw L spring E strip g spring J wire 3 plate f hand-lever Ewire a, binding-screw P and out-stations to ground.

It will here be noticed that a single handtelephone may be connectedwith either circuit, and it will be convenient to here observe that indiagram at a section 3 might be represented as an exact duplicate ofsection 2, having its binding-screws which would correspond to L and Mand which may be designated by L and M respectively connected with L andM by wires. Accordingly, when a corresponding hand-lever, E should bebrought down to the middle of a long lining-plate of a slot, 0 thehand-levers E and E remaining up, bindingscrews L and M would beconnected through bindingscrews L M L M with the hand-telephone, and thetelephone-circuit would be established in section 3 alone.

4. The person at the out-station who has called the central station,speaking through his telephone, makes known the other out-station withwhich he wishes to be put in communication; and for the present it issupposed that this second out-station belongs to section 2. The operatorat the central station, leaving the E hand-lever of the section of theparty calling-that is, in this instance Ein the position shown indiagram 2, brings down the F lever of the party callingtltat is, in thisinstance F-and places it in anynotch whose corresponding notch in anyother section upon the switch-board is not occupiedsay in 6 (see diagram4)-and then calls the party in section 2 who is wanted by pressinghand-lever E against binding-screw N a number of times corresponding tothat partys number in the section. This calling-circuitis from ground,through calling-battery at central office, to binding-screw N hand leverE wire 12', binding-screw P to out-stations, (including bellcircuits atout-stations,) and ground. The hand-lever E springs back to its normalposition at the top of lining-plate f when nott'orced against thebinding-screw N 5. The operator at the central station, after ringing upthe party in section 2, leaving the handlevers E and F of section 1,which is the section of the calling party, in. the positions laststated-that is, at the positions shown at section 1 in diagram 4bringsdown hand-leverF and places it in the notch of slot 1) corresponding tothe notch in which he has placed F-tl1at is, in this instance, in notch6 but the operator leaves hand-lever E undisturbed-that is, leaves itup. The circuit is then from ground, through out-stations of section 1by line-wire l, to binding-screw P, by wire 1; to hand-lever E, strip f,(in slot 0,) by wire y, spring J, brass strip g, spring H, binding-screwL, telephone '1, binding screw M, spring K, strip 9 spring S, wire r,handlever F, notch c, by wire w (passing through holes j j to notch 0hand-lever F wire 1, spring S strip g spring J wire y strip f (in slot 0hand-lever E wire a", bindingscrew. P to out-stations and ground.

6. It, when connection has been thus made, the party called does notanswer, he may be called again by simply pressing hand-lever E againstbinding-screw N it is obvious that the combined circuit just describedbut momentarily disturbed, for when hand-lever E is left free it springsback, as before stated, to lining-plate f 7. It answer is made, theoperator at the central station cuts his own telephone out by placingthe rod E in its normal position-4. e., upright. The circuit between thecommunicating parties is then, as shown in diagram 5, from ground andoutstation to binding-screw P, wire '0, hand-lever E, lining-platef",wire sections may be connected.

y, spring J, strip 9 spring S, wire 1*, and on as before in diagram 4.

In the same manner as it was shown that a telephone-circuit might beestablished between a section 3 and the hand-telephone, which islocatedin section 1, it might be shown that a telephone-circuit might beestablished between a section 4 and the same telephone, it beingsuflicient to say that a wire runs through all the L binding-screws t.0., L L L L L, &c.-and another wire through all the M binding-screws-t'.0., M M M M M 85c; and it is obvious that the hand-telephone might belocated at any other station as well as at station 1, except that it isconvenient to have it at the right of the casing. It only remains to addthat in like manner all the corresponding notches in the I) slotst'. 6.,in the slots 1) I) b 11 b Ste-are connected by a wire running throughthem all, and it follows that by placing any two of the F levers--z'.0., any two of F F F F 4 F &c.in corresponding notches of theirrespective slots, any two There should be as many notches in each 1)slot as there are 12 slots on the switch-board.

In diagram 3 1 have represented the manner in which a magneto-call maybe connected and used by the operator at the central station-that is,the lining-platef is in electrical connection with binding-screw ltwhich is connected, as indicated, with a magneto-generator and ground.To use the magneto-call the operator, instead of pressin g thehand-lever E against binding-screw N, as before directed, brings it downinto contact with lining-1i)la-tef when the magneto circuitisestablished, as indicated in diagram 3. When, therefore, the apparatusis constructed, as shown, so that the quadrants have four strips, it maybe used either with a call-battery, as represented in diagram 3,- orwith a 1nagiieto-gencrator, as represented in diagram 3. The shortstripsat the top of the quadrants g and g are used for grounding theirrespective telephone-circuits, the grounding binding-screws Q and Qbeing electrically connected with them, as before stated. Thehand-telephone at the central otfice is brought into the circuit, whichis thus grounded. The advantage ofthis is that when a connectionhas beenestablished between two sections the hand-tele1id1one may be used in thetelephone-circuit of either of them by simply bringing down the Ehand-lever in that section to the lower end of the long liningplate ofits slot, (see diagram 6,) and then the connection may be restored bysimply raising the same hand-lever. It, therefore, the open atorobserves that a third party has broken in, he uses this branch of theswitch to request that party to withdraw. So far as the switchboard isconcerned the connection is at no time essentially disturbed.

It may be well to add that all N binding screws are grounded through abattery and all 0 binding-screws are grounded through a call-bell. All Pbinding-screws are grounded through the out-stationsotthe sections towhich they respectivelybelong. AllQbinding-screws are simply grounded.

Each F lever is furnished with a spring, as shown in Fig. 4, whichcauses it to assume its normal position when released from an a notch.

I claiin 1. With two or more telephone-circuits, suitable contact platesand points, (fixedand movable,) connecting-wires, and aswitch-board, thecombination in each circuit of two switching hand-levers, respectively,for cminecting lines and for grounding or signaling, or both, andworking in parallel arcs on said switch-board, sul'istantially asdescribed.

2. The outwardly-curved vertically-slotted switch board, embodyingsuitable contactpoints, ground and line connections, in combination withswitching-levers which occupy slots in the curved board and are movablein parallel arcs toward and from the operator, substantially asdescribed.

3. On a switch board belonging to two or more telephone-circuits, thecombination, with separate switching mechanism, of a number of switchinghand-levers equal to the number of circuits, the several levers havinguniform motions, and eachbeing in electrical connection with saidseparate switch mechanism to bring in its own tele 'ihone-circuit, andworking in a slot provided with a series of notches, the correspondingnotches of said slots being also in electrical connection, substantiallyas described.

4. With two or more telephonecircuits, the COll'lblllfltlOll of aswitch-board and a number of switching hand-levers equal to the numberof circuits, the said hand-levers being located upon said switch-board,which is common to them all, and each working in a slot provided with aseries of notches, the corresponding notches of said slots being inelectrical connection, substantially as described.

5. The combination, substantially as hereinbefore described, ofswitching hand-levers for connecting and disconnecting two, or two ofseveral, telephonecircuits, and independent call-circuits having pointsor springs for contact with the switching hand-levers, whereby theselatter are available for bringing in the call-circuit as well as forconnecting and disconnecting the telephone-circuits.

6. The combination, substantially as hereinbeforc described, of two ormore switchinglevers working in parallel slots on a switchboard, andeach connected .with its own telephone-circuit, electric connections forconnecting one lever with another, a call battery at the central office,and electric connections for connecting either of said levers with thecallbattery, whereby, when telephone-circuits have been connecteththecall-battery may be brought in with but momentary disturbance of theconnected telephone-circuit.

7. Two or more telephone-circuits and a switch-board provided withcontact points and plates, fixed and movable, connectingwires, and apair of switching hand-levers for the telephone-circuits, ordisconnected thereeach circuit, co-operating substantially as defrom, orgrounded in any one circuit independ- 1o scribed, in combination with asingle handcntly of another, by Working the hand-levers telephone at acentral office, connected with appropriate to said circuit. 5 line andground bymeans of the switching- ELLIS F. FROST.

levers, substantially as described, whereby the Witnesses Y singletelephone may be used in any entire cir- J. W. ROSE, cuit formed by theunion of two or any two of W. W. SWAN.

